Conditions on this page are recalculated from the latest forecast every time it is opened, for the current date in the location's own time zone.
The ideal indoor humidity level is between 30% and 50% relative humidity. Below 30%, air becomes uncomfortably dry, causing irritated skin, static electricity, and respiratory discomfort. Above 50%, moisture promotes mold growth, dust mites, and a muggy feeling. Most HVAC experts recommend targeting 40–45%. Outdoor humidity above 60% starts to feel noticeably uncomfortable for most people because the body cannot efficiently cool itself through sweat evaporation. Above 70%, conditions feel oppressive. Above 80% combined with temperatures over 80°F (27°C), heat-related illness risk increases significantly. High humidity does not directly cause illness, but it creates conditions that promote health issues. Sustained indoor humidity above 60% encourages mold growth, dust mite proliferation, and bacterial growth, all of which can trigger allergies, asthma attacks, and respiratory infections. High humidity also impairs thermoregulation, increasing heat-related illness risk. Yes, significantly. The ideal bedroom humidity for sleep is 30–50%. Humidity above 60% makes it harder for your body to cool down during sleep, leading to restlessness, sweating, and reduced deep sleep phases. Very low humidity below 20% can cause nasal dryness and throat irritation that disrupts sleep. Water molecules in humid air conduct electricity and help dissipate static charges. When humidity drops below 30%, the air becomes an insulator, allowing static charges to build up on surfaces and your body. This is why static shocks are far more common in winter when indoor heating dries the air. Complete guide to humidity levels and their effects on health, comfort, and daily life. Learn the ideal humidity range, how to manage indoor moisture, and when outdoor humidity becomes dangerous. 75°F should feel comfortable. But at 85% humidity, it feels like 86°F — your shirt sticks, your skin drips, and every breath feels thick. Humidity is the invisible force that makes "nice" weather miserable and turns safe exercise into a heat emergency. Here's exactly how to read it. Relative humidity (RH) is the percentage of moisture the air currently holds compared to the maximum it could hold at that temperature. At 50% RH, the air contains half its moisture capacity. At 100% RH, the air is fully saturated — this is when fog, dew, or precipitation forms. The key word is "relative" — warm air can hold significantly more moisture than cold air. Air at 90°F with 50% RH contains far more water vapor than air at 40°F with 50% RH. This is why summer air feels muggy at 60% humidity while winter air at 60% feels merely damp. Quick Reference: Air at 86°F (30°C) can hold roughly 4 times more water vapor than air at 50°F (10°C). The same "50% humidity" reading feels dramatically different at each temperature. The 30–50% RH range is considered the sweet spot for human comfort, health, and building preservation. Within this range, your body can thermoregulate efficiently, respiratory membranes stay moist, and the environment inhibits most biological contaminants. When humidity exceeds 60%, your body's cooling system becomes compromised. Sweat cannot evaporate efficiently, so core temperature rises even during moderate activity. This significantly increases the risk of heat exhaustion and heat stroke, especially when combined with temperatures above 80°F (27°C). The feels-like temperature spikes because sweat cannot cool you. A 90°F day at 70% humidity feels like 106°F. Mold spores germinate above 60% RH. Dust mites thrive above 50%. Both trigger asthma and allergies. Your body needs to drop its core temperature to initiate deep sleep. High humidity prevents this. Mold can begin growing within 24–48 hours when indoor humidity consistently exceeds 60%. Common indoor mold triggers include poor ventilation in bathrooms and kitchens, unvented dryers, damp basements, and inadequate air conditioning. The EPA recommends keeping indoor humidity below 60% at all times, with 30–50% as the ideal target. Low humidity — typically below 30% — is common during winter in heated buildings, in arid climates, and at high altitudes. While often overlooked compared to high humidity, chronically dry air poses distinct health and comfort challenges. Dry mucous membranes are less effective at trapping viruses. Studies show flu virus survives longer in very dry air.
Scores are capped by dealbreakers — heavy rain, dangerous wind, thick fog or hazardous UV pull a day down no matter how pleasant the rest of the numbers look. Forecast data is Open-Meteo; solar and lunar values are computed for Humidity Levels Guide's own coordinates and time zone. Full details on the methodology page.